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United States Patent | 5,049,935 |
Saito ,   et al. | September 17, 1991 |
An electrophotographic image forming apparatus with reversal development system, wherein a photosensitive member is charged to first polarity by a first charger and then charged to second polarity opposite to the first polarity by a second charger which is provided at downstream side of the first charger with respect to the rotational direction of the photosensitive member prior to an image formation so as to form uniform images regardless of the number of image formation.
Inventors: | Saito; Hitoshi (Machida, JP); Eda; Masami (Itami, JP) |
Assignee: | Minolta Camera Kabushiki Kaisha (Osaka, JP) |
Appl. No.: | 652775 |
Filed: | February 8, 1991 |
Feb 10, 1990[JP] | 2-30978 |
Current U.S. Class: | 399/168; 347/140; 399/310 |
Intern'l Class: | G03G 015/02 |
Field of Search: | 355/227,204,221,225,219,245,223,271 346/160 |
4139942 | Jan., 1979 | Nakahata et al. | 355/222. |
4591262 | May., 1986 | Oseto et al. | 355/221. |
4623243 | Nov., 1986 | Iijima et al. | 355/219. |
4757345 | Jul., 1988 | Ohashi et al. | 355/219. |
4914457 | Apr., 1990 | Fukatsu et al. | 346/160. |
Foreign Patent Documents | |||
59-37500 | Sep., 1984 | JP. |